Question: Gabriela had to read papers 41 through 71 for homework last week. If Gabriela read all of the papers she was assigned, how many papers did she read?
Instead of counting papers 41 through 71, we can subtract 40 from each number so we instead consider papers 1 through 31. We see that Gabriela read 31 papers. Notice that she read 31 and not 30 papers.